As Alan Grant viewed the computer image of the recently excavated Velociraptor, he noticed that the head was bent backwards towards the posterior region. He mused that such findings had previously been common enough, that scientists had formulated a theory to explain it. This theory was that the contraction had arisen from the Dinosaur’s death agonies after being poisoned by the alkanoids in plant matter.Grant dispelled this theory, proving that many species of birds and lizards also showed a similar contraction upon death. Thus it had nothing to do with the cause of death, but how the carcass of the animal dried in the sun.
Jurassic Park by Michael Crichton page 56 (First Edition, Thirty Fourth printing